ICMPv6

Question 1

ICMPv6 Use cases

Answer 1

• Diagnostics
• Neighbor discover
• Multicast group management
• Issue notification
• Includes ARP (Address resolution protocol) and IGMP (Internet group messaging protocol)

Question 2

ICMPv6 Message format

Answer 2

In IP packets, long at most 576bytes

Question 3

ICMPv6 error message

Answer 3

t = 1: dest unreachable

t = 2: packet too big

t = 3: time exceeded

t = 4: parameter problem

Question 4

ICMPv6 Echo messages

Answer 4

request: type = 128
reply: type = 129

Question 5

ICMP Neighbor Solicitation/Adv Message

Answer 5

Question 6

ICMPv6 and multicast communication in the internet

Answer 6

Packets addressed to a multicast adress.

Process:

• Withing a link rely on mapping IPv6 addresses onto MAC multicast addr.
• Among links packets are routed by routers
  
  • ICMPv6 to konw on-link members (hosts that want to received packets)
  • Multicast routing protocols to know who are off-link memebers

ICMPv6 group managements;
Multicast listener query:

• General: routers asks if hosts are interested in an arbitrary group
• Multicast address specific query: router requests if hosts are interested in particular group

MC L report: hosts notifies router that wants to get multicast packets from a group

MC L done: hosts notifies that wants to stop receiving packets from multicast group